MOUNT VERNON, Maine—Living in the lush, wooded countryside with fresh New England air, Wendy Brennan never imagined her family might be consuming poison every day. But when she signed up for a research study offering a free T-shirt and a water-quality test, she was stunned to discover that her private well contained arsenic.

Brennan is not alone. Urine samples collected by the Centers for Disease Control and Prevention from volunteers reveal that most Americans regularly consume small amounts of arsenic. It’s not just in water; it’s also in some of the foods we eat and beverages we drink, such as rice, fruit juice, beer and wine.

Under orders from a Republican-controlled Congress, the Environmental Protection Agency in 2001 established a new drinking-water standard to try to limit people’s exposure to arsenic. But a growing body of research since then has raised questions about whether the standard is adequate.

The EPA has been prepared to say since 2008, based on its review of independent science, that arsenic is 17 times more potent as a carcinogen than the agency now reports. Women are especially vulnerable. Agency scientists calculated that if 100,000 women consumed the legal limit of arsenic every day, 730 of them would eventually get bladder or lung cancer from it.

After years of research and delays, the EPA was on the verge of making its findings official by 2012. Once the science was complete, the agency could review the drinking water standard. But an investigation by the Center for Public Integrity found that one member of Congress effectively blocked the release of the EPA findings and any new regulations for years.

It is a battle between politics and science. Mining companies and rice producers, which could be hurt by the EPA’s findings, lobbied against them. But some of the most aggressive lobbying came from two pesticide companies that sell a weed killer containing arsenic.

The EPA had reached an agreement with those companies to ban most uses of their herbicide by the end of last year. But the agreement was conditioned on the EPA’s completing its scientific review. The delay by Congress caused the EPA to suspend its ban. The weed killer, called MSMA, remains on the market.

Turning to a powerful lawmaker for help is one tactic in an arsenal used by industry to virtually paralyze EPA scientists who evaluate toxic chemicals. In 2009, President Obama signed an executive memorandum to try to stop political interference with science. That same year, the EPA unveiled an ambitious plan to evaluate far more chemicals each year than had been done in either the Bush or Clinton administrations.

But in 2012 and 2013, the EPA has managed to complete only six scientific evaluations of toxic chemicals, creating a backlog of 47 ongoing assessments. It’s a track record no better than past administrations. The Center found that a key reason for this is the intervention by a single member of Congress.

The story of arsenic shows how easily industry thwarted the Obama’s administration’s effort to prevent interference with science.

A ubiquitous poison
Arsenic is virtually synonymous with poison. But it’s also everywhere, found naturally in the Earth’s crust. Even if the toxin were eliminated from drinking water, people would still consume it in food, a more vexing problem to address.

Scientists are debating whether there is such a thing as a safe level of arsenic. New research has raised questions whether even low levels of arsenic can be harmful, especially to children and fetuses.

The findings of the study Wendy Brennan enrolled in were published in April. Researchers from Columbia University gave IQ tests to about 270 grade-school children in Maine. They also checked to see if there was arsenic in their tap water at home. Maine is known as a hot spot for arsenic in groundwater.

The researchers found that children who drank water with arsenic—even at levels below the current EPA drinking water standard—had an average IQ deficit of six points compared to children who drank water with virtually no arsenic.

The findings are eerily similar to studies of lead, a toxin considered so dangerous to children that it was removed from paint and gasoline decades ago. Other studies have linked arsenic to a wide variety of other ailments, including cancer, heart disease, strokes and diabetes.

“I jokingly say that arsenic makes lead look like a vitamin,” said Joseph Graziano, a Columbia professor who headed the Maine research. “Because the lead effects are limited to just a couple of organ systems—brain, blood, kidney. The arsenic effects just sweep across the body and impact everything that’s going on, every organ system.”

For 15 years, Brennan and her family drank water with arsenic levels five times greater than the current drinking-water standard. She has no way of knowing what effect this has had on her two daughters.

Carrington Brennan, now 14, says it bothers her to think that drinking water may have affected her intelligence. “It shocked and scared me, I guess,” she said. “I think it should be prevented in future cases.”

Chemical reviews lag
It’s the job of the EPA to protect the public from toxic chemicals. To do that, the agency must first review the scientific literature to determine which chemicals are harmful and at what doses. This duty falls on an obscure program with a drab bureaucratic name, the Integrated Risk Information System (IRIS).

There are tens of thousands of chemicals on the market and by one estimate, 700 new chemicals are introduced every year. Yet since 1987, IRIS has completed evaluations on only 557 of them.

The last time IRIS analyzed arsenic was in 1988, just a year before the Safe Drinking Water Act called for the EPA to set a new drinking-water standard for the toxin. The EPA missed that deadline, so in 1996, a Republican-controlled Congress gave the agency five more years to comply. The EPA turned to the prestigious National Academy of Sciences for help. Scientists there reviewed the EPA’s 1988 analysis. They said it was badly out of date and underestimated the risk of arsenic.

After the EPA set a new drinking-water standard in 2001, the IRIS program moved to update its analysis of arsenic. EPA scientists spent five years reviewing hundred of studies before sending a draft report to the White House’s Office of Management and Budget in October 2008.

EPA scientists concluded that arsenic was 17 times more potent as a carcinogen than the agency currently reports. Put another way, the risk of someone eventually getting cancer from drinking the legal limit of arsenic every day is 60 times greater than any other toxin regulated by drinking-water laws.

The White House at that point had become a nemesis of EPA scientists, requiring them to clear their science through OMB starting in 2004. Scientific assessments were often sent to OMB only to die, seemingly the victim of political influence. A stinging report by the Government Accountability Office in 2008 said that IRIS was at serious risk of becoming obsolete, unable to keep up with the workload or the science. The GAO noted that in 2007 the EPA sent 16 assessments to OMB, where they got held up. That year, the agency managed to complete only two assessments.

Within five months of Obama taking office, the EPA wrested back control of the process. The agency also set up an ambitious timetable to complete toxic-chemical assessments within two years. By that point, the arsenic assessment had already been in the works for six. The arsenic draft had to go through an external peer-review before being considered valid. But IRIS officials were optimistic about completing it by the end of 2011.

Meanwhile, in an entirely different office within the EPA, negotiations were under way that would ultimately prevent IRIS from finishing its work.

Groundwater fears
Veterans Community Park is one of the busiest parks in Naples, Fla., with softball fields, basketball and tennis courts and a playground. In early 2004, Collier County began spraying the herbicide MSMA on the fields to control weeds. But soon, tests detected high levels of arsenic in the groundwater.

It wasn’t the first time alarms had sounded about MSMA. Tests at nine golf courses using the weed killer had detected significant levels of arsenic in shallow groundwater and ponds, a concern because 90 percent of all drinking water in Florida comes from wells. The EPA had already banned all pesticides containing inorganic arsenic, considered to be the most toxic form of the metal. But evidence showed that the organic arsenic in MSMA converts to inorganic in soil. EPA scientists feared that MSMA could be contaminating drinking water.

In 2006, the EPA’s Office of Prevention, Pesticides and Toxic Substances announced plans to ban all uses of herbicides containing arsenic and began negotiating with the few companies still selling them. Within three years, they had reached an agreement. The pesticide companies would phase out all uses of MSMA, except on cotton fields, by the end of 2013.

But the agreement included a condition. It required the EPA to complete a scientific review of arsenic before the ban could take effect. The pesticide office apparently assumed that the IRIS assessment, then six years in the making, would be done by then.

In all likelihood, IRIS would have met the deadline. But two pesticide companies and their lobbyist turned to Congress.

The two companies are Drexel Chemical Co. of Memphis, Tenn., and Luxembourg-Pamol, whose parent, Luxembourg Industries, is based in Tel Aviv, Israel. Both are family-owned. Luxembourg-Pamol doesn’t release sales figures; Drexel Chemical says its sales exceed $100 million a year.

Though anyone can buy MSMA, the label cautions that it should be sprayed only on cotton fields, sod farms, highway shoulders and golf courses. The market for MSMA is likely worth several million dollars for these companies. The EPA estimated in 2006 that about 3 million pounds of MSMA and another similar compound were sold each year in the United States. The weed killer retails for about $5 a pound.

The companies joined forces to hire Charlie Grizzle, a lobbyist who worked as an EPA assistant administrator during the President George H. W. Bush era. When the EPA released a public draft of its arsenic assessment in February 2010, the pesticide companies countered with a unique argument.

Michal Eldan, a vice president at Luxembourg-Pamol, said her company had the scientific literature scoured and found 300 studies published since 2007 that the EPA had not included in the draft.

“If the report is not up to date, a risk assessment cannot be based on that,” Eldan said in an interview. “We mentioned that because this is the one inarguable detail. You can argue about toxicity. You can argue about risk assessment. You can’t argue about 300 publications that are missing from the list of references.”

Grizzle added, “I think it’s safe to say that the missing 300 studies, if you will, really exposed EPA to accusations from congressmen and stakeholders that they were cherry-picking the data.”

In August 2010, 15 Republicans in the House and Senate made that very argument in a letter to then-EPA Administrator Lisa Jackson: “We are informed that there are nearly 300 studies in the scientific literature on arsenic published since 2007 that were not included in the agency’s evaluation. We find that troubling and are concerned that this could allow critics to conclude that the agency is ‘cherry-picking’ data to support its conclusions."

After reading the letter, Michael Hansen, a senior scientist at Consumers Union who has followed the arsenic review closely, said, “This is a really dishonest couple of sentences ... That’s because the [EPA] document was written in early 2008, and the only reason the public is seeing it [in 2010] is because OMB sat on it.”

“It’s not cherry-picking the data. When the document was written, those studies hadn’t been published yet,” he said.

Yet the missing publications ultimately became the rationale for Congress to derail the EPA’s assessment. In July 2011, language appeared in a House Appropriations Committee report ordering the EPA to take no action on its arsenic assessment and turn the job over to the National Academy of Sciences. The report instructed the academy to include “the 300 studies in the published scientific literature EPA failed to review for its 2010 draft assessment.”

Committee reports explain how to implement a bill. Government agencies could ignore them, but they seldom do, for fear of angering congressional leaders who control funding. Burying language in a report — as opposed to the bill itself—was the same technique once used for earmarks. Steve Ellis, vice president of Taxpayers for Common Sense, a nonprofit group that closely monitors the Appropriations Committee, said rank-and-file members of the House cannot strike or amend language in a report. In fact, he said, only a couple of lawmakers in leadership would likely know who put the language in the report.

Rep. Chellie Pingree, a Maine Democrat on the subcommittee that oversees EPA funding, said she has no way of knowing who is responsible for trying to kill the arsenic assessment. “It’s happening more and more in this Congress that we see less and less of what goes on behind the scenes, that members aren’t informed until the last minute,” she said. “So things like this, major policy changes like this, can happen somewhat in the dark of the night with very little information to the public.”

So, who did it? All the evidence from the Center’s investigation pointed to one congressman: Mike Simpson of Idaho.

Simpson was one of the Republicans who signed the letter to the EPA administrator complaining about the missing 300 studies. He was the chairman of the subcommittee that controlled funding for the EPA, where the language first appeared. He was also a member of another committee where the language surfaced again in a different report. He even asked the EPA administrator about arsenic at a subcommittee hearing.

Simpson, who worked as a dentist and state legislator before entering Congress, is a frequent critic of the EPA. But in the 2012 and 2014 election campaigns, he has been portrayed as too liberal by Tea Party candidates funded by the right-wing Club for Growth.

In a brief interview outside his Capitol Hill office, Simpson accepted credit for instructing the EPA to stop work on its arsenic assessment. “I’m worried about drinking water and small communities trying to meet standards that they can’t meet,” he said. “So we want the Academy of Science to look at how they come up with their science.”

Simpson said he didn’t know that his actions kept a weed killer containing arsenic on the market. He denied that the pesticide companies lobbied him for the delay. But lobbyist Grizzle offered a different account. “I was part of a group that met with the congressman and his staff a number of years ago on our concerns,” Grizzle said, adding that there were four or five other lobbyists in that meeting but he couldn’t remember who they were.

Other organizations that disclosed lobbying the EPA and Congress on the agency’s arsenic evaluation were the U.S. Rice Federation; the Mulch and Soil Council; the Association of California Water Agencies; and the National Mining Association, including the mining companies Arch Coal and Rio Tinto.

Grizzle began making donations to Simpson’s re-election campaign in January 2011, a few months before Simpson took action to delay the arsenic assessment. Since then, Grizzle has given a total of $7,500. That’s more than he’s given in that time to any other candidate. Asked if the contributions were made in exchange for the delay, Grizzle said, “I don’t see a connection. I’ve been a friend and supporter of Congressman Simpson for a long time.” When Simpson was asked if he was aware of the donations, he terminated the interview, saying, “I have no idea. But I’ve got a hearing.”

Industry playbook
The National Academy of Sciences was created during the Civil War to provide objective advice from the nation’s most highly regarded scientists. In 1999 and 2001, the academy twice reviewed the EPA’s analysis of arsenic and concluded it badly underestimated the risk. The EPA’s draft that has been delayed was built in part off the academy’s critique.

Taking scientific assessments out of the hands of the EPA and giving them to the academy has become a tactic to delay regulations, said Charles Fox, a former EPA assistant administrator who oversaw the development of a new drinking water standard for arsenic. “The standard playbook that industry uses first begins with questioning the science, and they can question the science in any one of a number of different forms,” he said. “There is a scientific advisory board at EPA. There’s the National Academy of Sciences.”

But endless delays to perfect the science can jeopardize public health, Fox said. “We always as regulators had to do our best to make decisions based on the best available science we had at the time. Science will always improve and you can always revisit that decision down the road, but fundamentally we have an obligation to protect public health in the environment, and that decision needs to be made on the best science that you have today.”

In a letter last October telling buyers that the EPA had lifted its ban for at least three years, the MSMA manufacturers said in a joint statement that they “fully expect the NAS review to result in a less stringent risk value for human exposure to inorganic arsenic.” If so, the companies said, they are confident the threat of a ban will be lifted permanently and the EPA may even allow other uses of MSMA.

The two manufacturers of the herbicide are still trying to influence the scientific assessment. The National Academy held a meeting in April 2013 to review the science on arsenic. It invited 14 scientists to give presentations. Two of those scientists are funded by Drexel and Luxembourg-Pamol, which lobbied Simpson to delay the EPA.

The academy doesn’t require presenters to disclose their financial ties; some choose to do so and some don’t. Neither of the scientists funded by the pesticide companies disclosed their ties at the meeting.

Dr. Samuel Cohen, a professor at the University of Nebraska College of Medicine, told the panel that inorganic arsenic doesn't cause cancer or any other diseases in people below a certain threshold dose, which he suggests is substantially higher than the current drinking water standard. Cohen has been funded by the MSMA manufacturers for more than a decade, according to disclosures in published articles.

Barbara Beck, who works for Gradient, a scientific consulting firm often hired by industry, also gave a presentation without disclosing her ties.

Eldan, with Luxembourg-Pamol, acknowledged that both scientists are paid by her company. Beck prepared a 32-page report on the EPA’s arsenic assessment. Eldan said that Beck and Cohen disclose their ties in published articles in scientific journals. In some cases, Eldan, a scientist herself, is listed as a co-author.

Cohen said in an email that he disclosed his funding in published articles that he provided to the academy. Records show that Cohen sent the academy three articles that listed funding only from the “Arsenic Science Task Force,” with no further explanation about the task force.

Beck said, “Although I have done work for the Organic Arsenical Products Task Force [composed of the two pesticide companies], my presence and presentation at the April 2013 meeting were funded wholly by Gradient …. At both meetings, I am solely responsible for my comments.”

Joseph Graziano, who chairs the National Academy of Sciences panel on arsenic, said he hadn’t realized that Beck and Cohen were being funded by the pesticide companies when they spoke at the workshop. “I was not aware of that,” he said, “and I don’t think the committee was aware of it.”

Congress rescues the formaldehyde industry
This is not the first time Congress has pressured the EPA to hand over science on toxic chemicals to the National Academy. In 2009, Sen. David Vitter, a Republican from Louisiana, held up the nomination of a top EPA official as leverage to force the agency to have the academy review the risks of formaldehyde.

The World Health Organization’s International Agency for Research on Cancer and the National Institute of Health’s National Toxicology Program both say that formaldehyde can cause cancer. The EPA was preparing to say the same.

Yet the agency ultimately relented to Vitter’s demand. After months of review, the academy criticized the IRIS draft on formaldehyde for being repetitive, poorly organized and failing to clearly present all the evidence of its findings. The panel recommended the EPA redo the draft to be more clear and concise. Recognizing that the EPA was having a problem in completing assessments, the academy said it wasn’t calling for a delay.

Soon, however, the formaldehyde industry was turning to Congress to help it delay the assessment. Right next to Simpson’s language in the committee report about delaying the arsenic assessment was another set of instructions to the EPA. This time, IRIS was told to apply the academy’s recommendations on formaldehyde to all ongoing and future assessments. When asked if he requested the language, Grizzle acknowledged only that he was one of the lobbyists for the Formaldehyde Council, an arm of the industry.

The EPA said in a report to Congress it won’t start all its assessments over from scratch, but it will try to incorporate the academy’s recommendations. As a result, the 47 pending reviews have been further delayed.

IRIS Director Vincent Cogliano said the changes will lead to more rigorous assessments that should have an easier time getting through peer review. When asked how IRIS responds to political pressure, he said he had little control over that. “We’re doing our best to keep our assessments focused on the science,” he said. “What happens after that is not part of the IRIS process.”

‘It’s not their right’
Eldan said people shouldn’t be worried about her company’s weed killer. “To be honest, we believe that this is a good product, that it does not pose a concern to health and the environment,” she said. Clearing weeds from the sides of highways can be a safety issue, she said, because tall plants can block vision. Even on golf courses, there are safety concerns, she said. “The weeds have a tendency to spread. If you don’t use herbicides, it’s not only one weed. They can cover the golf course,” Eldan said. “The players can stumble on them.”

Meanwhile, in Maine, Wendy Brennan worries about all the years her family was drinking arsenic-tainted water. “I know a lot of people around the area that have had cancer, and so you always think, ‘Jesus, that's going to be my kids. It’s going to be me or my husband,’ ” Brennan said.

Her congresswoman, Pingree, also worries about her constituents. “When you have a toxic chemical in the environment that could be affecting child development or people who could eventually be contracting cancer from their exposure to this, we shouldn’t be delaying,” Pingree said.

She fears that after the National Academy of Sciences completes its review, the pesticide companies will find another delaying tactic. “That’s the sad part; there’s nothing to stop Congress from finding another roadblock to delay,” Pingree said. “Congress can say, ‘Well, here’s another 200 studies, you better review them.’ ”

Brennan doesn’t understand why there’s a need to wait. “If they’ve already got some proof that it’s 17 times more potent, you’d think they’d want to get the information they had out and then continue to explore scientifically more,” she said. “We need to know what’s going on with our drinking water. If somebody wants to not let us know because they want to keep some pesticides making money for five more years…it's not their right. It’s not their body. It’s not their decision.”